libviper
===========

libviper: A library for controlling the image processing IP on Renesas devices.
	  libviper is the Video and Image Processing Engine for Renesas (VIPER).
	  libviper is a user-space library designed to make accessing and
	  controlling the V4L2 drivers for Renesas IP easier.  It does NOT
	  directly control the hardware, and as such a functioning V4L2 driver
	  for the corresponding image processing IP is necessary to use
	  libviper.

Copyright (C) 2014 IGEL Co., Ltd.

This source archive contains:

 * src/libviper: the libviper shared library
 * src/tools: commandline tools
 * include/shvio: backwards compatible headers for libshvio

libshvio compatibility
----------------------

libviper supports a backwards compatibility mode that will allow for using
some of the funtionality of libshvio from within libviper.  This allows
the VIO hardware to be used from multiple processes simultaneously.  libviper
operates on virtual addresses, and so has the following differences from
libshvio:
	* All virtual addresses passed to libviper must be actual virtual
	  addresses, capable of being derefernced by the CPU
        * shvio_set_dst_phys/shvio_set_src_phys are not supported.

If the above limitations are met, libviper should be a drop-in replacement
for libshvio.

libshvio API
------------

libshvio provides simple scale and rotate capability via the shvio_resize and
shvio_rotate blocking functions.
	vio = shvio_open()
	do {
		shvio_resize(vio, ...);
	} while (processing);
	shvio_close(vio);

For more flexibility, such as operating on a selection of a larger frame the
shvio_setup function can be used along with shvio_start and shvio_wait.
	vio = shvio_open()
	do {
		shvio_setup(vio, ...);
		shvio_start(vio);
		shvio_wait(vio);
	} while (processing);
	shvio_close(vio);

For low latency and reduced memory use, bundle mode is supported via the
shvio_start_bundle function. Using this mode requires that the input and output
buffer addresses are updated before the start of the next bundle.
	vio = shvio_open()
	do {
		shvio_setup(vio, ...);
		do {
			shvio_set_src(vio, ...);
			shvio_set_dst(vio, ...);
			shvio_start_bundle(vio, ...);
			end = shvio_wait(vio);
		} while (!end);
	} while (processing);
	shvio_close(vio);

Please see doc/libshvio/html/index.html for API details.

Test programs
-------------

Several test programs are available in the src/tools directory. Currently,
all of these tools use the libshvio API.  libviper API tools will be coming
in time.

License
-------

See the file COPYING for details.